Render Crash / CUDA error
Out of memory errors can always be traced to the same source:


  Your scene and render settings exceed the resources available in your computer.


You've set subdivision surface settings for Render to a high number, some have it set to 6!



Do you need that many polygons? There is a huge penalty for using such large values:

For every subdivision level the number of polygons increases exponentially.

At level six you are generating 4225 extra quads for every quad of the original object... Enough to choke most computers.

Use proper modeling and less subsurf to describe the shape of the objects. You should rarely need more than a subsurf level of 3. Straight shapes with flat faces might not need any subsurf at all.

Read: Blender render crash when using subsurf modifiers..

Also keep in mind that denoising will use a lot of memory, as it has to keep information from all the surrounding tiles.

Read: Why does Denoising take up so much memory? 

Try reducing the tile size as well.